As soon as possible after the date on which a petition is filed under section 2271 of this title, but in any event not later than 40 days after that date, the Secretary shall determine whether the petitioning group meets the requirements of section 2272 of this title and shall issue a certification of eligibility to apply for assistance under this subpart covering workers in any group which meets such requirements. Each certification shall specify the date on which the total or partial separation began or threatened to begin.

A certification under this section shall not apply to any worker whose last total or partial separation from the firm or appropriate subdivision of the firm before his application under section 2291 of this title occurred—

Upon reaching his determination on a petition, the Secretary shall promptly publish a summary of the determination in the Federal Register together with his reasons for making such determination.

Whenever the Secretary determines, with respect to any certification of eligibility of the workers of a firm or subdivision of the firm, that total or partial separations from such firm or subdivision are no longer attributable to the conditions specified in section 2272 of this title, he shall terminate such certification and promptly have notice of such termination published in the Federal Register together with his reasons for making such determination. Such termination shall apply only with respect to total or partial separations occurring after the termination date specified by the Secretary.